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Dodd, Robert T.

Publications and source records attributed to Dodd, Robert T..

An H chondrite stream - Identification and confirmation

Fall data indicate that a significant, elongate cluster of co-orbital H chondrite falls in May between 1855 and 1895 (H Cluster 1) records encounters with two or three closely spaced and probably related meteoroid stream components, each of which was met near its perihelion. Although meteorites included in the cluster vary widely in petrographic type, shock facies, and Ne-21 exposure age, they have a distinct labile trace element signature that confirms a common thermal history and, thus, a common source region within an H chondrite parent body. Hence, meteorites selected by one criterion (fall parameters) as distinguishable from all other H chondrites, are distinguished from them by another completely different criterion (contents of labile trace elements).

Dodd, Robert T.↗

Overview and classification of meteorites

Before interpreting properties of meteorites in terms of putative processes and conditions in the early solar system, it is necessary to understand just what sort of objects meteorites are. Such understanding begins with classification. In this chapter, the current taxonomy of meteorites is summarized, and it is shown how certain stone meteorites, the chondrites, possess chemical and petrographic features that make them potentially attractive as probes of the early solar system. The prevalence of secondary alteration effects, often capable of perturbing the primitive record even in chondrites, is also emphasized.

Sears, Derek W. G.↗

Thermal metamorphism

Most chondrites have experienced thermal metamorphism, resulting in changes in texture, mineralogy and possibly chemical composition. The physical conditions for metamorphism range from approximately 400 to 1000 C at low lithostatic pressure. Metamorphism may have resulted from decay of short-lived radionuclides, electromagnetic induction or accretion of hot materials. Several thermal models for chondrite parent bodies have been proposed. The least metamorphosed type-3 chondrites probably carry the most information about the early solar system, but even these have been affected to some degree by thermal processing.

Mcsween, Harry Y., Jr.↗